Four-slide machine with improved mandrel for producing bearings and the like

ABSTRACT

A high production machine of the vertical four-slide type for intermittently advancing strip stock, severing blanks therefrom, forming the same into bearing races and welding end portions thereof together. The machine has a projecting horizontal mandrel with three work stations there along respectively for preforming, forming, and preheating and/or welding. A cut-off anvil, transfer pins, broaching tools, and an expandable mandrel section are provided all with rear motion drive action and a welding mechanism is adapted for both preheat and weld operation adjacent the expandable mandrel section. A bearing race discharge track extends from the welding station to an induction furnace.

United States Patent Cavagnero et a].

FOUR-SLIDE MACHINE WITH IMPROVED MANDREL FOR PRODUCING BEARINGS AND THE LIKE Inventors: Erman V. Cavagnem, Torrington, Conn;

Joseph I". Loltus, Springfield, Ohio Assignee: Torin Corporation, Torrington, Conn.

Filed: June 8, 1970 Appl. No.: 44,483

Related U.S. Application Data Division of Ser. No. 721,672, April 16, 1968.

U.S. Cl. ..72/399, 72/391, 29/1496 C, 59/22, 72/402 Int. Cl .3211! 41/00 Field of Search ..72/39 I 394, 399, 398, 400,

72/403, 405, 402; 59/22, 23, 24, 18; 29/1484 R, 149.5 R, 1495 A, 149.5 C; 219/56 References Cited UNITED STATES PATENTS 3,559,263 2/1971 Cavagnero et al. ..29/148.4 R 1,964,584 6/1934 Klocke ..72/404 1,892,555 12/1932 Leis 29/1495 C 1,924,230 8/1933 Davis ...29/l49.5 C 2,712,835 7/1955 SampatacosWM..................l u.59/23 FOREIGN PATENTS OR APPLICATIONS 205,050 8/1924 Great Britain 1.59/22 Primary EraminerCharles W. Lanham Assistant Examiner-Michael J. Keenan Attorney-McComxick, Paulding & Huber 1 1 ABSTRACT A high production machine of the vertical four-slide type for intemiittently advancing strip stock, severing blanks therefrom, forming the same into bearing races and welding end portions thereof together, The machine has a projecting horizontal mandrel with three work stations there along respectively for prefonning, forming, and preheating and/or welding. A cut-0E anvil, transfer pins, broaching tools, and an expandable mandrel section are provided all with rear motion drive action and a welding mechanism is adapted for both preheat and weld operation adjacent the expandable mandrel section A bearing race discharge track extends From the welding station to an induction fumace.

fiClalim, IBDrawlngFlgures P'A'TENTEDJUL 1 1 [s72 sum 01 ur 11 INVENTORS ERMAN \l. CAVAGNERO JOSEPH F LOFTUS ATTORNEYS PATENTEDJUL H 1972 3.675.460

sum near 11 FIG. 2 I

PATENTEDJuL H 1972 3, 675.460

sum 03 or 11 FIG. 4

PATENTEDJuL 1 1 I972 sum as or 11 P'ATEmmJuL 1 1 m2 SHEET 08 0F 11 PATENTEDJULH 1972 3,575,450

sum uanr 11 PAIENTEnJuL 1 T 1912 3, 575.46g

sum 11 or 11 FEED FIG. l8

STOCK CLAMP CUT OFF I TOP TOOL 204 SIDE TOOLS A EXPANDER 0 I46 27! TRANSFER 2 PINS 0 BROACH 63 24X 297 WELD 160 PRE HEAT CURRENT |e9 238 334' PRE HEAT WELD I l l l I l l L 1 0 30 60 |20 l80 2|0 240 270' 300 330' 360' FOUR-SLIDE MACHINE WITH IMPROVED MANDREL FOR PRODUCING BEARINGS AND THE LIKE CROSS-REFERENCE TO RELATED APPLICATION This application is a div'mional from our copending US. application Ser. No. 721,672 filed Apr. 16, I968 entitled MACHINE FOR PRODUCING BEARINGS AND THE LIKE FROM STRIP STOCK.

BACKGROUND OF THE INVENTION This invention relates generally to a machine of the fourslide type and, more specially, to a four-slide machine particularly adapted to produce welded bearing races and the like from a strip stock at a high rate of production and at economic advantage. I-Iigh production machinery for producing commercially acceptable welded bearing races from strip stock has not heretofore been available.

SUMMARY OF THE INVENTION It is the general object of the present invention to provide a machine of the type mentioned wherein bearing races and the like, as well as other work pieces, can be formed from blanks severed from strip stock in a high speed operation and in a highly efficient and precise manner.

In fulfillment of this object, a four-slide machine is provided with the conventional hub-spoke tool arrangement about a center form or mandrel and; in addition, a plurality of additional tools or workpiece engageable devices are provided adjacent the mandrel and at least some of said devices are driven by suitable actuating or operating means disposedon a side of the machine frame opposite the mandrel. The additional tools or devices may comprise a movable mandrel part which in the preferred form comprises an expansion device operable in association with welding electrodes and clamps for preheat and weld operations. Further, one of said additional devices or tools may comprise a broaching tool operable upon end portions of a bearing race or other workpiece prior to preheating and/or welding of the workpiece. The expansion device has general utility but is particularly adapted to the manufacture of high carbon steel bearing races requiring a preheat-weld operation and the broaching tool finds advantage in the manufacture of both high and low carbon steel bearing races in the provision of clean, freshly exposed surfaces immediately prior to welding. Each of the devices mentioned is also usable to advantage in the manufacture of a wide variety of products other than bearing races and, accordingly the invention is not to be construed as limited to any specific type of workpiece or machine product.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a front elevational view of a vertical four-slide machine constructed in accordance with the present invention.

FIG. 2 is an enlarged fragmentary horizontal section taken generally as indicated at 2-2 in FIG. I with parts omitted for clarity of illustration.

FIG. 3 is an enlarged fragmentary vertical section taken generally as indicated at 3-3 in FIG. 2 with parts omitted for clarity of illustration.

FIG. 4 is an enlarged vertical transverse section taken generally as indicated at 4-4 in FIG. 1 with parts omitted for clarity of illustration, and which illustrates a first embodiment of a center form or mandrel.

FIG. 5 is an enlarged fragmentary longitudinal vertical section taken generally as indicated at 55 in FIG. 4.

FIG. 6 is an enlarged fragmentary longitudinal vertical section similar to FIG. 5 but showing a second embodiment of a center form or mandrel.

FIG. 7 is an enlarged fragmentary vertical elevational view of a rear portion of the machine showing operating means for workpiece engageable devices such as tools disposed at a front portion of the machine adjacent the mandrel.

FIG. 8 is an enlarged fragmentary horizontal section taken generally as indicated at 8-8 in FIG. 7 and showing the second center form or mandrel embodiment at FIG. 6.

FIG. 9 is an enlarged fragmentary transverse vertical sectional view taken generally as indicated at 9-9 in FIG. 8 with parts omitted for clarity of illustration.

FIG. 10 is an enlarged fragmentary vertical elevational view taken at the front of the machine and illustrating a preheat and welding mechanism.

FIG. 11 is an enlarged fragmentary transverse vertical sections] view taken generally as indicated at II-II in FIG. 1 with parts omitted for clarity of illustration.

FIG. 12 is an enlarged fragmentary transverse vertical sectional view taken generally as indicated at 12-12 in FIG. 1 with parts omitted for clarity of illustration.

FIG. I3 is an enlarged fragnentary top view taken generally as indicated at 13-13 in FIG. 1 and partially illustrating the operating means of FIG. 7.

FIG. I4 is an enlarged fragmentary vertical elevational view taken at the rear of the machine and further illustrating the operating means of FIGS. 7 and I3.

FIG. 15 is a somewhat schematic illustration showing an end portion of a center fonn or mandrel, a discharge track, a retaining device, and an induction furnace.

FIG. 16 is an enlarged fragmentary vertical front elevational view illustrating electrodes and clamps of the welding mechanism of FIG. 10, the electrodes and clamps being shown in a preheat condition.

FIG. I7 is an enlarged fragmentary front elevational view showing the electrodes and clamps of FIG. 16 in a weld condition.

FIG. 18 is an illustrative timing chart for the machine of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS GENERAL ORGANIZATION In the drawings a four-slide machine of the vertical type is i]- lustrated and will be described hereinbelow. It should be noted, however, that the invention is not limited to vertical four-slide machines and that directional or geometrical tenns such as verticaP', "horizontal", front, rear", forwardly" rearwardly, etc. are employed for convenience of description only and are not to be taken as limitations in the specification or in the claims which follow.

Referring particularly to FIG. 1, a vertical four-slide wire or strip forming machine is indicated generally at 10 with a cyclically operable intermittent feed mechanism 12 at a lefthand position, a cyclically operable press section I4 approximately at a central position, and a cyclically operable fonning and welding section 16 at a righthand position. Wire or strip generally indicated at 18 passes from left to right in the machine and is initially introduced to a straightener 20 which may be of conventional design and construction. The strip I8 is of a cross-sectional configuration conforming to that of a finished bearing race and the machine I0 will be described in conjunction therewith. It is to be noted, however, that the feed mechanism I2, the press section 14 and the forming and welding section [6 may be adapted to handle wire or strip having various cross-sectional configurations. Accordingly, terms such as wire and strop" are to be construed in a broad sense and as reflecting the capability of the machine in handling a continuous thread or slender rod of metal of any crosssectional shape such as round, square, triangular, flat or irregular.

The feed mechanism 12 is operated from suitable cams and gears deiven by an upper horizontal cam shaft 22 and includes an oscillable lever 24 and an associated grip and release mechanism 26 which intermittently feeds the strip I8 rightwardly along a horizontal and longitudinally extending path to the pres section I4 and the forming and welding section 16. For further illustration and description of the feed mechanism 12, reference may be had to Werner Vogt US. Pat. No. 3,052,392 entitled Wire Forming Machine".

The press section 14 is driven from the upper cam shaft 22 and includes cam or eccentric operated press tools 28, 28 which cooperate with a die or anvil unit 30. In the manufacture of bearing races on the machine 10, the press tools serve to provide transversely elongated slots between connecting marginal portions and which partially define race end portions in the strip 18. Further, the tools 28,28 are adapted to form the partially defined end portions as required for accurately sizing the finished race and efficiently welding together the end portions thereof. A presently preferred form of bearing race end portion shaping is illustrated and further explained in co-pending US. Pat. application Ser. No. 706,2 l 7, entitled, Welding Method For Bearing Races and Other Articles" in the name of Erman V. Cavagnero.

As the strip 18 is further advanced from left to right from the pressing section 14 leading end sections thereof are severed at the aforesaid transverse slots by a vertically reciprocable cut-off tool 32. Severed leading end sections form work pieces or bearing race blanks disposed adjacent a centerform or mandrel 34 and which are held in position for forming about the mandrel by means of a stock clamp or check 36. As shown, the center form or mandrel 34 extends generally horizontally forwardly from a vertical machine frame 38 and the stock check 36 is associated with but operable independently from an upper vertically reciprocable tool 40 which cooperates with the mandrel 34. A lower vertically reciprocable tool 42 and left and right hand horizontally reciprocable tools 44, 46 also cooperate with the mandrel 34 in forming a bearing race blank or other workpiece. As will be apparent, the tools 40, 42, 44, and 46 are arranged generally in a hub-spoke configuration in a vertical plane about the mandrel 34 for reciprocation toward and away from the mandrel. Suitable slides are provided for the tools 40 to 46 and are driven from the aforementioned upper horizontal cam shaft 22, a iower horizontal cam shaft 48 and vertical left and right hand cam shafts 50, 52. The cam shafts are arranged in parallel pairs in a vertical-horizontal rectangular configuration and generally in a vertical plane. Suitable bevel gear connections are provided between the cam shafts 22, 48, S and 52 for rotation of the shafts in unison. A driving connection for the lower horizontal cam shaft 48 is provided in the form of an appropriate gear 62 rotated indirectly from a power operating means which may take the form of an electric motor 63. Cams 64, 66, 68 and 70, respectively mounted on the shafts 22, 48, S0 and 52, operate the tools 40, 42, 44 and 46 in timed relationship with other machine elements.

A welding mechanism 72 at the forming section 16 cooperates with the mandrel 34 in preheat and/or weld operations on workpieces. The welding mechanism is driven by an oscillable level 74 and a cam 76 on the shaft 52, and wiil be described more fully hereinbelow.

REAR MANDREL WORK STATION In the manufacture of welded bearing races, the machine of the present invention is preferably provided with a series of work stations along the mandrel 34 extending from a rear portion thereof to a front portion thereof, and there is also preferably provided a transfer device for advancing workpieces forwardly along the mandrel in timed relationship with the operation of tools at the several work stations.

At a rear work station, a leading end section of an advancing strip is severed to provide a unitary work piece in the form of a linear bearing race blank and the blank is thereafter formed to a partially circular configuration. In FIGS. 2 and 3 the strip 18 is shown advanced atop an anvil 78 and transversely atop a rear mandrel portion 340. The vertically reciprocable cut-off tool 32 cooperates with the anvil 78 in the strip cutoff operation and is mounted on the aforesaid upper vertically reciprocabie tool 40 for operation therewith. In operation, and in its downward or operative stroke, the tool 40 moves downwardly approximately to the position shown in FIG. 3 whereby to effect a cut-off operation through cooperation of the tool 32 and the anvil 78. Thereafter, the tool 40 is withdrawn upwardly to enable the cut-ofl' tool 32 to clear the strip 18 and, subsequently, the tool 40 is again moved downwardly to effect partial forming of a severed bearing race blank. Once a leading end section of the strip 18 has been severed to provide a bearing race blank, the anvil 78 is withdrawn horizontally rearwardly from its operative position beneath the strip 18 whereby to provide clearance for downward arcuate movement of a trailing edge portion of the blank during subsequent partial forming of the latter, FIG. 3. As best illustrated in FIG. 12, the anvil 78 is adapted for horizontal reciprocable movement in forward and rearward directions by connection with a horizontal slide 80 at the rear of the machine frame 38. The slide 80 is in turn connected with an oscillable lever 82 pivotally supported at 84 and driven by a cam 86 having a track 88. The cam 86 is mounted on a stub shaft 90 which also carries a gear 92 rotated by an intermediate gear 94, in turn engaged with a drive gear 96 on the aforesaid upper horizontal cam shaft 22, FIGS. 12 and 13. Thus, it will be apparent that forward and rearward strokes of the anvil 78 can be provided for in suitably timed relationship with the vertical cut-ofl' strokes of the tool 32 in the cyclic operation of the machine.

Returning now to FIGS. 2 and 3, it will be apparent that on withdrawal of the anvil 78 the second and forming portion of the stroke of the tool 40 can be effected. On occurrence of the forming portion of the tool stroke the bearing race blank is bent at least approximately to the position 18a of FIG. 3 about the enlarged rear mandrel portion 34a. Inward or operative strokes of the side tools 44, 46 are effected approximately at the same time and preferably slightly later than the stroke of the upper or top tool 40 whereby to complete the partial forming of the blank to the precise position shown in FIG. 3. Precise timing is of course provided for in conventional design of the cams 64, 68 and 70 and cam track configuration will be readily apparent from the timing chart of FIG. 18.

The aforementioned stock check 36 is operable during the aforesaid sequence of operations in a conventional manner to engage an advanced leading end section of the strip 18 and to securely hold the same in engagement with the enlarged mandrel rear section 34a.

In accordance with one aspect of the present invention, the forming machine has at least one tool in addition to the aforementioned vertically reciprocable tools disposed adjacent the mandrel and which is adapted to be entered between the end portions of a partially formed workpiece and carry out an operation on the workpiece. In the manufacture of bearing races two such additional tools are provided and take the form of broaching tools 98, 98, FIG. 3. The broaching tools 98,98 are arranged to engage and to work upon the end portions of a partially formed race such as I8a and to complete the aforementioned sizing and shaping functions prior to welding of the end portions together. It is to be noted also that the breaching tools provide clean, freshly exposed surfaces conducive to efficient welding in an extremely shon increment of time prior to welding. Thus, there is little or no opportunity for oxidation or other contamination at the end portions prior to welding.

The broaching tools 98, 98 are arranged for horizontal reciprocable movement and, in their operative stroke, they are drawn rearwardly in engagement with end portions of a partially formed race such as at the rear or performing sta tion of the mandrel 34. As best illustrated in FIG. 8, the broaching tools 98, 98 extend rearwardly through suitable openings in the rear mandrel portion 34a and the machine frame to an L-shaped bracket I00 attached to and movable forwardly and rearwardly with a slide I02. The slide 102 is pivotally connected with an upper end portion of an oscillable cam lever 104 by means of suitable pin I06, and the lever 104 extends downwardly behind the machine frame 38 and is driven at a lower end portion by means of a cam 108 on the lower horizontal cam shaft 48, FIG. 1. Thus, it will be apparent that the broaching tools 98,98 can be reciprocated in timed relationship with the tools 40, 44, 46, etc. and in the manner illustrated by the timing chart of FIG. 18 whereby effectively to breach end portions of a partially formed bearing race 18a.

A chip exhaust means is also preferably provided and may comprise ports 1 10, 1 10, one shown in FIG. 8, communicating with the broaching tool at its rearward position and extending to an evacuating conduit 112. Conventional vacuum generating means may be conveniently located at a rear portion of the machine. Further, a jet of air is preferably blown across the broaching tools in their retracted position and an appropriate air inlet port (not shown) may be provided adjacent the tool in such position as to cooperate with the evacuating port 1 10.

On completion of preforming and broaching at the rear mandrel station, the aforementioned transfer device operates to advance a bearing race forwardly along the mandrel to an intermediate station for further forming. in its presently preferred form, the transfer device comprises four transfer pins 114, 114 reciprocable in unison along the mandrel and arranged in a generally rectangular configuration to engage and urge a bearing race forwardly to the intermediate station. The pins 114, 114 extend rearwardly through the machine frame 38 and through suitable openings in the L-shaped bracket 100 to a horizontally reciprocable L-shaped slide 116, FIG. 8. Rear portions of the pins are fixedly secured to the slide 116 and the latter is movable forwardly and rearwardly at the urging of a pivot pin 118 engageable with an upper end portion of an oscillable cam lever 120. The cam lever 120 ex tends downwardly behind the frame 38 of the machine and is driven at a lower end portion by means of a cam 122 on the lower cam shaft 48, FIG. 1. Thus, the pins 114, 114 can be reciprocated to advance partially formed bearing races from the rear mandrel station to the intermediate station in timed relationship with the operation of tools and other machine elements.

Preferably, magnetic means are provided in the form of inserts on the pins 114,114, an electromagnet, or magnetized pins to provide for magnetic retention of a bearing race in precise registry on the ends of the transfer pins 114,114. The stock check 36 is, of course, operable in timed relation with the transfer pins to hold, release, and again hold respectively at the rear work station, during transfer, and at the intermediate work station.

INTERMEDIATE MANDREL WORK STATION At the intermediate or forming mandrel work station, a partially formed bearing race is further formed to a circular configuration as indicated at 18b with end portions thereof in contiguous relationship for welding. Various tooling arrangements are of course possible, but it is the preferred practice to provide for further forming at the intermediate station by means of the aforementioned upper and lower tools 40, 42. At the intermediate work station, the mandrel 34 has a section 34b, FIG. 4, which is of cylindrical configuration and the upper tool 40 has a work engaging surface 126 which is approximately semi-cylindrical for engagement with an upper portion of a partially formed bearing race 18a. The lower tool 42 has a similar work engaging surface 128 which engages a lower portion of the bearing race for finish forming. The left and right hand tools 44 and 46 are inoperative at the intermediate work station.

As will be apparent, bearing race formation at the rear and intermediate stations can take place simultaneously. That is, while one bearing race is being partially formed as described above at the rear work station a second and preceding race can be finish formed at the intermediate work station for subsequent transfer forwardly to an additional work station along the mandrel.

For transferring bearing races or other workpieces from the intermediate work station to an additional or front work station along the mandrel, the aforesaid transfer device is provided with a second set of transfer pins. Four such pins are preferably provided and are indicated at 128,128 in a rectangular configuration spaced to engage a finish formed bearing race at the intermediate station.

The transfer pins 128,128 extend rearwardly through the frame of the machine as best illustrated in FIG. 8, two shown, and are fixedly attached at rear end portions to the slide 116 for operation in unison with the aforementioned transfer pins 114,114. As in the case of the pins 114,114, the transfer pins 128,128 are preferably magnetized so as to magnetically retain a bearing race such as 18b at the front end portions thereof. Further, it is to be observed that the length and stroke of the transfer pins 128,128 are determined so as to provide for a slight overtravel and return motion during transfer. That is, the transfer pins 128,128 engage a bearing race 18b at the intermediate station and, in an operative stroke, the pins urge the race forwardly along the mandrel to the position 18c and slightly beyond such position, FIG. 4, and thereafter withdraw the race to the position 18:. Thus, a preceding bearing race at the position 18c is engaged by an advancing bearing race and moved forwardly along the mandrel so as to be discharged from the front work station and to provide for a slight space between such preceding bearing race and the race advanced to the front work station. While such spacing of the races has obvious general advantages in the discharge of races from the front work station, there is also a particular advantage derived when welding is carried out at the front work station, such advantage being set forth hereinbelow.

FRONT MANDREL WORK STATION While various tools may be provided for operation on workpieces at a front mandrel work station in a machine constructed in accordance with the invention the said station is preferably employed as a preheat and/or welding station in the production of bearing races. ln the manufacture of low carbon steel bearing races, the aforementioned welding mechanism 72 is employed for welding only but in the manufacture of high carbon steel bearing races, preheating is necessary or at least desirable, and, accordingly, both preheating and welding operations are carried out at the front work station. The manufacture of welded high carbon steel bearing races of high quality and structural integrity is a particularly difficult task and preheating and welding steps must be carried out within exacting requirements. The welding method employed in the operation of the welding mechanism 72 is fully described in aforementioned co-pending US. application Ser. No. 706,217 entitled "Welding Method For Bearing Races and Other Articles in the name of Erman V. Cavagnero.

in FIGS. 4 and 5, a fixed cylindrical mandrel section 34c is shown at the front work station and said mandrel configuration may be employed in the manufacture of low carbon bearings wherein a welding operation only is carried out at the said station. Thus, welding clamps 130,130 in the mechanism 72, FIG. 10, are swung inwardly into engagement with a bearing race at the front work station for welding together the end portions of the race. The clamps 130,130 have associated electrodes 132,132 connected by suitable cables 134,134 to a conventional electrical welding supply unit 136 shown atop the forming machine in FIG. 1. Swingable arms 138,138 respectively carry the clamps 130,130 and the electrodes 132,132 and are pivotally supported at 140 above the mandrel by means of a bracket 142 secured to the machine frame. At lower end portions the arms 138,138 are pivotally connected respectively with operating rods 144,144. The rods 144,144 are in turn connected with the aforementioned cam lever 78 which is of a generally T-shaped configuration and which carries spaced pivot pins 146,146 on the arms of the T portion thereof for connection with the rods. At a location intermediate the ends of the mm of the T portion a pivot pin 148 supports the lever 76 for oscillation thereabout at the urging of the cam 76. The pivot pin 148 is in turn supported by a bracket 150 secured to the machine frame.

As will be apparent in FIGS. 1 and 10, an upward movement at the right hand end portion of the cam lever 74 at the urging of the cam 76 will result in a counterclockwise movement of the lever exerting a push" action on the upper rod 144 connected to the right hand arm 138 and in a pull" action exerted on the lower rod 144 connected to the left hand arm 138. Such actions of course tend to close the clamps 130,130 and the electrodes 132, 132 about a bearing race on the mandrel 34 for a welding operation at the end portions thereof. Conversely, a downward movement at the right hand end portion of the lever 74 at the urging of the cam 76 results in clockwise movement of the lever about the pivot 148 and in an opening movement of the clamps 130,130 and the electrodes 132, 132.

Preferably, a resilient biasing means is incorporated in association with the rods 144,144 and such means takes the form of a series of small annular tubes arranged in axial stacks at 152,152. The stack of tubes 152 associated with the upper rod 144 in FIG. 10 is maintained in compression between seats 154, 156 on closing movement of the clamps and electrodes and the stack of tubes 152 on the lower rod 144, while disposed on an opposite side of the pivot pin will nevertheless reside in compression between a seat 158 and a further seat, not shown, when the clamps and electrodes are closed. Engageable fixed and adjustable closing stops for the clamps and electrodes are provided respectively at 160 and 162.

When both preheating and welding are to be accomplished at the front mandrel station in the manufacture of high carbon steel bearing races, it is the preferred practice to provide a mandrel such as that shown at 164 in FIGS. 6, 8, 9, 1 1, 16 and 177 The mandrel 164 has a movable workpiece engageable part operable from behind the machine frame and usable for a wide variety of purposes but which takes the form of a race expansion device in the manufacture of high carbon steel bearing races. Three expansion elements 166,166 are preferably provided for engagement with the interior surface of a bearing race at the front work station and for expansion of the race during a preheating operation. As best illustrated in FIG. 16 the elements 166,166 engage interior surfaces of the bearing race at the front station while the clamps 130,130 and the electrodes 132,132 engages exterior surfaces thereof with end portions 168, 168 of the race thereby maintained in spaced relationship. The expansion of the elements 166,166 is such that the space between the end portions 168,168 of the race is sufficient to prevent arcing and current flow thereacross and in consequence, current flow occurs instead from one electrode 132 through an opposite or upper portion of the race to the other electrode 132 for preheating of the race. The electrodes 132,132 are similarly located and arranged generally on opposite sides of the bearing race and they are preferably disposed substantially closer to the end portions of the race than to a point on the race diametrically opposite the end portions. It is found that cold spots" may occur in the race beneath the electrodes and in order to limit the circumfercntial extend thereof it is believed that each electrode should not extend over more than one-fourth the bearing race circumference. Further, it is believed that optimum results are achieved when each electrode extends over approximately one-eighth the race circumference as shown.

Further with regard to FIGS. 16 and 17, it will be observed that a pair of small elements 170,170 are provided at an upper portion of the clamps 130,130 and that a similar pair of elements 172,172 are provided at a lower portion thereof adjacent the end portions of the bearing race 168. Said elements comprise wear resistant inserts, it having been determined that maximum clamp wear occurs at the locations thereof.

it will be apparent from the foregoing that suitable timing of electrode and clamp engagement with a bearing race, together with a properly determined welding current, will provide a preheating operation of desired characteristics as set forth in the aforementioned method application Ser. No. 706,217. When preheating is complete, the expansion elements |66,l66 urc collapsed to the position shown in FIG. 17 and additional force is exerted upon the bearing race by the clamps 130,130 through their aforedescribed operating means, reference being had to the timing chart of FIG. 1B. Thus, the end portions 168,168 of the bearing race are urged into firm pressure engagement as illustrated in FIG. 17 and current flow commences from one electrode 132 through the said end portions 168, 168 to the opposite electrode 132, the path through the end portions being substantially shorter than the path through the opposite or upper portion of the race. Thus, the end portions of the race are welded together in a resistance upset butt welding operation and a completed bearing race is provided.

Still referring to FIG. 17, it will be observed that the expansion elements 166,166 are shown in engagement with an interior surface of the bearing race 18c during the welding operation. It is the presently preferred practice to collapse the elements 166,166 sufliciently so that no substantial force is exerted thereby upon the interior surface of the bearing race during welding. It is contemplated, however, that some advantage may be derived in partially collapsing the elements 166,166 whereby to exert a slight but significant force upon the interior race surface during welding and thereby to aid in the uniform distribution of pressure by the clamps about the exterior race surface. In the timing chart of FIG. 18 the broke line portion adjacent the term Expander" represents the latter condition wherein slight pressure is applied during welding, and the full line portion thereof represents the former condition wherein substantially no pressure is applied by the elements 166,166 during welding. Conventional cam design practice can, of course, be followed in providing for either alternative condition through operation of an actuating means for the elements 166,166 to be described presently.

In FIGS. 8 and 9, it will be observed that the expansion ele ments 166,166 are pivotally supported for generally radial movement by means of small pins 174,174 at rear end portions thereof. Inner surfaces 176,176 of the elements are inclined from the horizontal for camming cooperation with similarly inclined surface 178 on a frusto-conical member 180 at a forward end portion of an actuator 182. The actuator ex tends rearwardly through a suitable axial opening in the mandrel 164 and is connected at a rear end portion with a bracket 184, FIG. 9, in turn connected with a slide 186 disposed behind the machine frame 38. The slide 186 carries a pivot pin 188 which in turn carries a short connecting link 190 pivotally connected at 192 to an oscillable cam lever 194. As best illustrated in FIG. 11, the cam lever 194 is pivotally supported at 196 and extends upwardly to a cam 198 wherein its cam follower 200 is entered in a track 202 for timed oscillation of the lever 194. The cam 198 is mounted on and driven by the aforementioned stub shaft as best illustrated in FIGS. 13 and 14. Thus, it will be apparent that the lever 194, the slide 186 and the actuator 182 can be operated from the upper cam shaft 22 for operation of the expansion device of the mandrel 164 in timed relationship with the welding mechanism, transfer device, etc. When the frusto-conical member is drawn rearwardly to the position shown in FIG. 8 and in FIG. 9 in full line, the elements 166,166 are urged to their outer or radially expanded condition of FIG. 16. Conversely, operation of the cam, lever, slide, etc. in an opposite direction urging the actuator 182 and frusto-conical member 180 forwardly to the FIG. 9 broken line position allows the elements 166,166 to move inwardly to the collapsed condition of FIG. 17.

DISCHARGE TRACK AND INDUCI'lON FURNACE In the manufacture of bearing races it is presently the preferred practice to provide for a postheat means and such means in the form of an induction furnace 204 is illustrated schematically in FIG. 15. A bearing race discharge track 206 extends rearwardly from the furnace to an end surface of a mandrel such as the mandrels 34, 166 and is arranged to receive bearing races advanced along the mandrel from the front work station thereon. Further, a retaining means is preferably provided for securing a bearing race such as the race 18c in position on the track. When a race is advanced to the front work station so as to urge a preceding race at the station forwardly along the mandrel and to space the same from the station as described above, the said preceding bearing is moved to and held at the position 18d. Particularly in the case of high current welding, magnetic forces are generated in the area of the welding clamps and electrodes and such forces tend to withdraw a race such as the race 18d rearwardly into engagement with the clamps, etc. A retaining means such as 208 secures a race 18d in position on the track 206 and prevents the same from moving rearwardly under the influence of such magnetic forces.

The retaining means 208 may vary widely in design and construction but presently takes the form of a small fluid operable cylinder 210 having a reciprocable rod 212 engageable with a bearing race 18d to secure the same in position. The cylinder 210 may be operated by electrical control means represented schematically at 214 under the regulation of a small cam 216 which may be mounted upon one of the aforementioned cam shafts such as the shaft 22. Thus, the earn 216 controls the operation of the cylinder 210 to urge the rod 212 downwardly into engagement with a bearing race as it is advanced to the position 18d and when a subsequent race is advanced the rod will release the race at 18d allowing preceding races to be moved thereby along the track 206, and the rod will then return to its operative position in engagement with the advanced bearing race.

I claim:

1. The combination in a wire or strip forming machine of a vertical frame, at least two parallel interconnected cam shafts supported in a generally vertical plane by said frame, a mandrel supported by the frame and projecting generally horizontally forwardly therefrom, said mandrel having a first part which is fixed relative to said frame and at least one additional part which is engageable with workpieces and movable between at least two radial positions, and operating means for changing the position of said movable mandrel part and which extends rearwardly from the part through said frame and is connected with and driven from one of said cam shafls, means for successively feeding workpieces transversely of said mandrel to a position adjacent thereto, a plurality of tools movable in generally vertical planes and at least some of which are arranged in a hubspoke configuration about said mandrel, and means connected with said cam shafts for operating said tools in timed relationship with said movable mandrel part and for forming successive workpieces about said mandrel.

2. The combination in a wire or strip forming machine as set forth in claim 1 wherein four interconnected cam shafts are provided in parallel pairs and in a generally horizontal-vertical rectangular configuration about the mandrel, and wherein cams on the shafts and associated tool slides are provided for the reciprocal operation of tools within the rectangular configuration of the shafis and generally toward and away from said mandrel.

3. The combination in a wire of strip forming machine as set forth in claim 1 wherein said fixed mandrel part has a longitudinally extending opening therein, and wherein said operating means for said movable mandrel part comprises an elongated member entered in and movable in said opening at the urging of further elements of the operating means at a rear portion thereof behind said frame.

4. The combination in a wire or strip forming machine as set forth in claim 3 wherein said mandrel includes at least two movable parts having inner and outer radial positions for operation on an adjacent workpiece, and wherein said elongated member is movable axially within said mandrel opening and connected at a forward portion with said parts for movement of the latter between said inner and outer positions.

5. The combination in a wire or strip forming machine as set forth in claim 3 wherein said further elements of said operating means comprise cam means on one of said shafis and oscil lable lever means disposed behind said frame and connected between said cam means and said elongated member.

6. The combination in a wire or strip forming machine as set forth in claim 3 wherein said mandrel has at least two work stations therealong in rear-tofront order with at least one tool operable at said front station, wherein said movable mandrel part is located at said from station, and wherein a transfer device is provided for successively advancing workpieces from said rear to said front work station.

7. The combination in a wire or strip forming machine as set forth in claim 6 wherein fliree work stations are provided along said mandrel with said movable mandrel part located at the forwardmost station, wherein at least one said tool is operable at each said station, and wherein said transfer device successively advances workpieces along said mandrel to said work stations seriatim.

8. The combination in a wire or strip forming machine as set forth in claim 1 wherein two of said tools cooperate with said movable mandrel part and comprise opposing electrodes engageable with workpieces on the mandrel, said movable mandrel part serving to deflect workpieces from their free configuration during electrode engagement therewith. 

1. The combination in a wire or strip forming machine of a vertical frame, at least two parallel interconnected cam shafts supported in a generally vertical plane by said frame, a mandrel supported by the frame and projecting generally horizontally forwardly therefrom, said mandrel having a first part which is fixed relative to said frame and at least one additional part which is engageable with workpieces and movable between at least two radial positions, and operating means for changing the position of said movable mandrel part and which extends rearwardly from the part through said frame and is connected with and driven from one of said cam shafts, means for successively feeding workpieces transversely of said mandrel to a position adjacent thereto, a plurality of tools movable in generally vertical planes and at least some of which are arranged in a hubspoke configuration about said mandrel, and means connected with said cam shafts for operating said tools in timed relationship with said movable mandrel part and for forming successive workpieces about said mandrel.
 2. The combination in a wire or strip forming machine as set forth in claim 1 wherein four interconnected cam shafts are provided in parallel pairs and in a generally horizontal-vertical rectangular configuration about the mandrel, and wherein cams on the shafts and associated tool slides are provided for the reciprocal operation of tools within the rectangular configuration of the shafts and generally toward and away from said mandrel.
 3. The combination in a wire of strip forming machine as set forth in claim 1 wherein said fixed mandrel part has a longitudinally extending opening therein, and wherein said operating means for said movable mandrel part comprises an elongated member entered in and movable in said opening at the urging of further elements of the operating means at a rear portion thereof behind said frame.
 4. The combination in a wire or strip forming machine as set forth in claim 3 wherein said mandrel includes at least two movable parts having inner and outer radial positions for operation on an adjacent workpiece, and wherein said elongated member is movable axially within said mandrel opening and connected at a forward portion with said parts for movement of the latter between said inner and outer positions.
 5. The combination in a wire or strip forming machine as set forth in claim 3 wherein said further elements of said operating means comprise cam means on one of said shafts and oscillable lever means disposed behind said frame and connected between said cam means and said elongated member.
 6. The combination in a wire or strip forming machine as set forth in claim 3 wherein said mandrel has at least two work stations therealong in rear-to-front order with at least one tool operable at said front station, wherein said movable mandrel part is located at said front station, and wherein a transfer device is provided for successively advancing workpieces from said rear to said front work station.
 7. The combination in a wire or strip forming machine as set forth in claim 6 wherein three work stations are provided along said mandrel with said movable mandrel part located at the forwardmost station, wherein at least one said tool is operable at each said station, and wherein said transfer device successively advances workpieces along said mandrel to said work stations seriatim.
 8. The combination in a wire or strip forming machine as set forth in claim 1 wherein two of said tools cooperate with said movable mandrel part and comprise opposing electrodes engageable with workpieces on the mandrel, said mOvable mandrel part serving to deflect workpieces from their free configuration during electrode engagement therewith. 